A field study was conducted in Tucson, Ariz., in 1987 to evaluate the dispersal of cotton (Gossypiumspp.) pollen grains by honey bees,Apis melliferaL., in relation to distance from pollen source and time-of-day. The experimental field consisted of 10 rows with rows 1 and 2 planted to both male-fertile upland cotton (G. hirsutumL.) (south end) and male-fertile Pima cotton (G. barbadenseL.) (north end). Rows 3 to 10 were planted with an upland cytoplasmic male-sterile line. The hourly pattern of pollen deposition on the stigmas of male-sterile lines was determined from 0800 to 1600 hours (MDST). The highest number of upland or Pima pollen grains deposited on the stigmas of male-sterile lines was from the rows nearest to the pollinator rows. The peak time of pollen deposition on the stigmas was between 1000 and 1200 hours. These data indicate that the distance across which bees transfer pollen is a factor in choosing the optimum combination of male-fertile and male-sterile lines, and a reduction of pollen loads on stigmas during the afternoon hours may result from accidental pollen removal by honey bees.